Jonson — The Law of Dissipation -of Motion. 579 



the two components AD and CD which are of opposite 

 direction. 



The probability that the paths of initial motion of two 

 colliding particles will exactly coincide is zero, because 

 there is an infinity of possible degrees of eccentricity of 

 collision. The actual relative motion of two colliding 

 particles, therefore, must be regarded as eccentric. 



When two moving particles collide and thus become the 

 points of application of a force each particle receives 

 from the other an additional momentum of the same 

 numerical magnitude but of opposite direction. If the 

 paths of initial motion of the two particles do not coin- 



FlG. 1. 



cide these added motions are not parallel with the initial 

 motions, but the added motion is a deflecting motion as 

 indicated in figure 2. 



Take two particles with the respective initial momenta 

 AB and BC, each receiving an additional momentum, the 

 momentum BD being added to AB and the momentum 

 DB to BC. If one of the initial momenta, say AB, is 

 greater than the other initial momentum, BC, the dif- 

 ference AC between the two initial momenta is greater 

 than the difference between the two resultant momenta 

 AD and DC. - To demonstrate this proposition it is neces- 

 sary only to consider that since the sum of the lengths of 

 two sides of a triangle is greater than the length of the 

 third side AC plus DC is greater than AD. If DC be 

 deducted from both quantities it is seen that AC is 

 greater than AD minus DC. In other words, the differ- 

 ence between the initial momenta is greater than the 

 difference between the resultant momenta. 



